Process of underground gasification of coal

Claim 1

AN IMPROVED PROCESS FOR RAPIDLY GASIFYING LARGE AREAS OF UNDERGROUND CARBONACEOUS MINERALS WITH A MINIMUM OF UNDERGROUND WORK, INVOLVING THE SIMULTANEOUS USE OF A PLURALITY OF BOREHOLES FROM THE SURFACE OF THE GROUND TO THE BED OF THE CARBONACEOUS MINERAL, COMPRISING THE STEPS OF FORMING A GALLERY OF CONSIDERABLE LENGTH IN A BED OF CARBONACEOUS MINERAL, FORMING A FIRST SET OF BOREHOLES COMMUNICATING FROM THE SURFACE WITH SAID GALLERY, FORMING A PLURALITY OF ADDITIONAL SETS OF BOREHOLES ESSENTIALLY PARALLEL TO, AND SPACED LATERALLY FROM SAID FIRST SET AND FROM EACH OTHER, AND EXTENDING FROM THE SURFACE TO SAID BED OF CARBONACEOUS MINERAL INITIATING COMBUSTION WITHIN SAID GALLERY, SUPPLYING OXYGEN-CONTAINING GAS TO SAID BED THROUGH ALTERNATE BOREHOLES OF SAID FIRST SET THEREBY MAINTAINING A COMBUSTION ZONE ALONG SAID GALLERY AT THE FACE OF SAID CARBONACEOUS MINERAL, REMOVING THE GASES PRODUCED FROM INTERVENING BOREHOLES OF SAID FIRST SET, CONTINUING TO SUPPLY OXYGEN-CONTAINING GAS TO, AND TO REMOVE PRODUCED GAS FROM, SAID FIRST SET OF BOREHOLES THEREBY ADVANCING THE COMBUSTION ZONE TOWARD SAID SECOND SET OF BOREHOLES ALONG A LINE ESSENTIALLY PARALLEL TO SAID GALLERY, TRANSFERRING THE OPERATIONS OF SUPPLYING OXYGENCONTAINING GAS AND OF REMOVING PRODUCED GASES TO SAID SECOND SET OF BOREHOLES AS THE COMBUSTION ZONE REACHES SAID SECOND SET, AND CONTINUING TO ADVANCE SAID COMBUSTION ZONE IN LIKE MANNER TOWARD SUCCESSIVE SETS OF BOREHOLES, THEREBY RAPIDLY AND SYSTEMATICALLY ADVANCING SAID COMBUSTION ZONE INTO SAID BED OF CARBONACEOUS MINERAL ALONG A LINE ESSENTIALLY PARALLEL TO SAID INITIAL GALLERY.